VulnerabilityPublished 8 Jul 2026Updated 17 Oct 2026

CVE-2026-59883: Guzzle · Prior to 7.12.3, CookieJar did not restrict cookies scoped to IP-address or bare-numeric Domain values to the exact host that set them, because

Affects guzzleSource GCVE Database

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Not known to be exploited · CVSS 6.1 Medium · fixed in 7.12.3 : update guzzle when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

6.1Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 7.12.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.10guzzle`pkg:deb/ubuntu/guzzle?arch=source&distro=stonking`Other threats	Affected 7.9.2-0.1build1 – 7.15.3-1 5 affected builds	Fixed in–
Ubuntu 26.04 LTSguzzle`pkg:deb/ubuntu/guzzle?arch=source&distro=resolute`Other threats	Affected =7.9.2-0.1 =7.9.2-0.1build1	Fixed in–
Ubuntu 25.10guzzle`pkg:deb/ubuntu/guzzle?arch=source&distro=questing`Other threats	Affected =7.9.2-0.1	Fixed in–
Ubuntu 24.04 LTSguzzle`pkg:deb/ubuntu/guzzle?arch=source&distro=noble`Other threats	Affected =7.4.5-1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Guzzle PHP HTTP client to version 7.12.3 or later, where the CookieJar component properly restricts cookies scoped to IP addresses or bare-numeric domains to the exact host that set them. No other mitigations are specified or required.

Description

Guzzle PHP HTTP client versions prior to 7.12.3 have a vulnerability in the CookieJar component where cookies scoped to IP addresses or bare-numeric domains are not properly restricted to the exact host that set them. This improper domain matching can lead to cross-host cookie disclosure, cookie injection, or session fixation attacks. The issue is fixed in version 7.12.3.

Impact

Exploitation of this vulnerability can lead to cross-host cookie disclosure, allowing an attacker to access cookies set by another host on the same IP or numeric domain. It also enables cookie injection or session fixation attacks, which can compromise user sessions and authentication integrity. The CVSS score of 6.1 (medium severity) reflects the potential for partial confidentiality and integrity impact without availability impact.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Oct 2026, 04:35 UTC

Technical details

References

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